diff --git a/res/fg/rock1lt.png b/res/fg/rock1lt.png
new file mode 100644
index 0000000..79c5297
Binary files /dev/null and b/res/fg/rock1lt.png differ
diff --git a/res/fg/rock1rt.png b/res/fg/rock1rt.png
new file mode 100644
index 0000000..3ade725
Binary files /dev/null and b/res/fg/rock1rt.png differ
diff --git a/res/resources.res b/res/resources.res
index da127e1..dd5dd7b 100644
--- a/res/resources.res
+++ b/res/resources.res
@@ -9,6 +9,8 @@ IMAGE rock1r "fg/rock1r.png" FAST
 IMAGE rock1b "fg/rock1b.png" FAST
 
 IMAGE rock1t "fg/rock1t.png" FAST
+IMAGE rock1lt "fg/rock1lt.png" FAST
+IMAGE rock1rt "fg/rock1rt.png" FAST
 
 SPRITE nitori "player/nitori.png" 4 4 FAST
 
diff --git a/src/foreground.h b/src/foreground.h
index b6bc5bc..9a2f24b 100644
--- a/src/foreground.h
+++ b/src/foreground.h
@@ -4,9 +4,13 @@
 #define FG_W GAME_W_T + 30
 #define OBSTACLE_COUNT 8
 
+#define FG_SPEED FIX16(2)
+#define FG_SPEED_NORM FIX16(1.414)
+
 struct obstacle {
-	bool active;
+	bool active, top;
 	Vect2D_f16 pos;
+	s16 startX;
 };
 struct obstacle obstacles[OBSTACLE_COUNT];
 
@@ -27,24 +31,58 @@ static void drawFg(){
 
 // obstacle
 
+#define OBS_CEIL_Y CEIL_Y + 4
 #define OBS_FLOOR_Y FLOOR_Y - 4
-s16 fgPos;
-s16 obsX;
+#define OBS_X 32
 
-static void spawnObstacle(){
-	obsX = 32;
-	VDP_drawImageEx(BG_B, &rock1l, TILE_ATTR_FULL(PAL2, 1, 0, 0, FG_I + 32), obsX, OBS_FLOOR_Y, 0, DMA);
-	VDP_drawImageEx(BG_B, &rock1, TILE_ATTR_FULL(PAL2, 1, 0, 0, FG_I + 48), obsX + 2, OBS_FLOOR_Y, 0, DMA);
-	VDP_drawImageEx(BG_B, &rock1r, TILE_ATTR_FULL(PAL2, 1, 0, 0, FG_I + 64), obsX + 2 + 4, OBS_FLOOR_Y, 0, DMA);
-	VDP_drawImageEx(BG_B, &rock1b, TILE_ATTR_FULL(PAL2, 1, 0, 0, FG_I + 80), obsX + 2, OBS_FLOOR_Y + 4, 0, DMA);
+s16 fgPos;
+
+static void spawnObstacle(bool top){
+	s16 i = -1;
+	for(s16 j = 0; j < OBSTACLE_COUNT; j++) if(!obstacles[j].active && i == -1) i = j;
+	if(i > -1){
+		obstacles[i].active = TRUE;
+		obstacles[i].top = top;
+		obstacles[i].pos.x = FIX16(256);
+		obstacles[i].startX = OBS_X;
+		if(top){
+			VDP_drawImageEx(BG_B, &rock1lt, TILE_ATTR_FULL(PAL2, 1, 0, 0, FG_I + 32), OBS_X, OBS_CEIL_Y - 2, 0, DMA);
+			VDP_drawImageEx(BG_B, &rock1t, TILE_ATTR_FULL(PAL2, 1, 0, 0, FG_I + 48), OBS_X + 2, OBS_CEIL_Y, 0, DMA);
+			VDP_drawImageEx(BG_B, &rock1rt, TILE_ATTR_FULL(PAL2, 1, 0, 0, FG_I + 64), OBS_X + 2 + 4, OBS_CEIL_Y - 2, 0, DMA);
+			VDP_drawImageEx(BG_B, &rock1b, TILE_ATTR_FULL(PAL2, 1, 0, 0, FG_I + 80), OBS_X + 2, OBS_CEIL_Y - 4, 0, DMA);
+		} else {
+			VDP_drawImageEx(BG_B, &rock1l, TILE_ATTR_FULL(PAL2, 1, 0, 0, FG_I + 32 + 80), OBS_X, OBS_FLOOR_Y, 0, DMA);
+			VDP_drawImageEx(BG_B, &rock1, TILE_ATTR_FULL(PAL2, 1, 0, 0, FG_I + 48 + 80), OBS_X + 2, OBS_FLOOR_Y, 0, DMA);
+			VDP_drawImageEx(BG_B, &rock1r, TILE_ATTR_FULL(PAL2, 1, 0, 0, FG_I + 64 + 80), OBS_X + 2 + 4, OBS_FLOOR_Y, 0, DMA);
+			VDP_drawImageEx(BG_B, &rock1b, TILE_ATTR_FULL(PAL2, 1, 0, 0, FG_I + 80), OBS_X + 2, OBS_FLOOR_Y + 4, 0, DMA);
+		}
+	}
+}
+
+#define OBSTACLE_MOD FIX16(8)
+#define OBSTACLE_LIMIT_X FIX16(-64)
+
+static void killObstacle(s16 i){
+	obstacles[i].active = FALSE;
+	if(obstacles[i].top){
+		VDP_clearTileMapRect(BG_B, obstacles[i].startX, OBS_CEIL_Y, 8, 8);
+		for(u8 i = 0; i < 2; i++) VDP_drawImageEx(BG_B, &rock1t, TILE_ATTR_FULL(PAL2, 1, 0, 0, FG_I),obstacles[i].startX + 4 * i, CEIL_Y, 0, DMA);
+	} else {
+		VDP_clearTileMapRect(BG_B, obstacles[i].startX, OBS_FLOOR_Y, 8, 8);
+		for(u8 i = 0; i < 2; i++) VDP_drawImageEx(BG_B, &rock1, TILE_ATTR_FULL(PAL2, 1, 0, 0, FG_I + 16), obstacles[i].startX + 4 * i, FLOOR_Y, 0, DMA);
+	}
+}
+
+static void updateObstacle(s16 i){
+	obstacles[i].pos.x = fix16Sub(obstacles[i].pos.x, FG_SPEED);
+	if(obstacles[i].pos.x <= OBSTACLE_LIMIT_X){
+		killObstacle(i);
+	}
 }
 
 
 // update
 
-#define FG_SPEED FIX16(2)
-#define FG_SPEED_NORM FIX16(1.414)
-
 #define FG_SIZE 32
 #define FG_LIMIT FIX16(-320)
 
@@ -70,10 +108,12 @@ static void scrollFg(){
 
 void loadFg(){
 	drawFg();
-	spawnObstacle();
+	spawnObstacle(FALSE);
+	spawnObstacle(TRUE);
 }
 
 void updateFg(){
 	VDP_setHorizontalScrollTile(BG_B, 0, fgPosX, GAME_H_T, DMA);
 	scrollFg();
+	for(s16 i = 0; i < OBSTACLE_COUNT; i++) if(obstacles[i].active) updateObstacle(i);
 }
\ No newline at end of file